The Collaborative International Dictionary of English v.0.48:

Crabbed \Crab"bed\ (kr?b"b?d), a. [See Crab,n.]
   1. Characterized by or manifesting, sourness, peevishness, or
      moroseness; harsh; cross; cynical; -- applied to feelings,
      disposition, or manners.
      [1913 Webster]

            Crabbed age and youth can not live together. --Shak.
      [1913 Webster]

   2. Characterized by harshness or roughness; unpleasant; --
      applied to things; as, a crabbed taste.
      [1913 Webster]

   3. Obscure; difficult; perplexing; trying; as, a crabbed
      author. "Crabbed eloquence." --Chaucer.
      [1913 Webster]

            How charming is divine philosophy!
            Not harsh and crabbed, as dull fools suppose.
                                                  --Milton.
      [1913 Webster]

   4. Cramped; irregular; as, crabbed handwriting. --
      Crab"bed*ly, adv. -- Crab"bed*ness, n.
      [1913 Webster]

WordNet (r) 3.0 (2006):

crabbed
    adj 1: annoyed and irritable [syn: crabbed, crabby, cross,
           fussy, grouchy, grumpy, bad-tempered, ill-
           tempered]

Moby Thesaurus II by Grady Ward, 1.0:

142 Moby Thesaurus words for "crabbed":
   Byzantine, acerb, acerbate, acerbic, acescent, anile, balled up,
   bearish, beyond one, bitchy, blunt, brusque, cankered,
   cantankerous, choleric, churlish, complex, complicated, confounded,
   confused, convoluted, crab, cramp, cranky, cross, cross-grained,
   crusty, cussed, daedal, debilitated, decrepit, devious, difficult,
   disagreeable, doddered, doddering, doddery, dour, dry, elaborate,
   embrangled, entangled, excitable, feeble, feisty, fossilized,
   fouled up, fractious, garbled, gerontal, gerontic, gloomy, glum,
   green, gruff, hard, hard to understand, huffish, huffy, implicated,
   infirm, intricate, involuted, involved, irascible, irritable,
   jumbled, knotted, knotty, labyrinthian, labyrinthine, loused up,
   many-faceted, matted, mazy, mean, meandering, messed up, mixed up,
   morose, mossbacked, moth-eaten, mucked up, multifarious, mummylike,
   obfuscated, obscure, obscured, ornery, overtechnical, palsied,
   papery-skinned, perplexed, perverse, pickled, pungent, ramified,
   ravaged with age, rickety, roundabout, run to seed, rusty,
   saturnine, scrambled, screwed up, sec, senile, shaky, shriveled,
   snappish, snarled, sour, sour as vinegar, soured, sourish,
   spiteful, spleeny, splenetic, stricken in years, subtle, sulky,
   surly, tangled, tangly, tart, tartish, testy, timeworn, tottering,
   tottery, tough, twisted, ugly, unripe, unsweet, unsweetened,
   vinegarish, vinegary, waspish, weak, withered, wizened